The purpose of this research is to study mechanisms participating in the pathogenesis of clinical hypertension. The renin-angiotensin system will be studied by specific blockade with saralasin or captopril and by measurement of components of this system in plasma. The role of the sympathetic nervous system will be assessed by measurement of plasma catecholamines, responses to defined stress (isometric handgrip exercise) and specific alpha and beta adrenergic blockade. A special emphasis will be placed on clinical glucocorticoid hypertension as found in Cushing's Syndrome or those with chronic administration of pharmacologic doses of glucocorticoids.